AT&T presents a circus in two acts by Cirque du Soleil. Produced by Cirque du Soleil. Directed by Franco Dragone; costumes, Dominique Lemieux; sets, Michel Crete; composer, Benoit Jutras; choreographer, Debra Brown; lighting, Luc Lafortune; sound, Francois Bergeron; artistic director, Andrew Watson. Opened, reviewed Sept. 26, 1996; runs through Nov. 24. Running time, 2 hours, 45 min. When Cirque du Soleil first emerged in 1984, seemingly from some dream world, the French Canadian troupe offered spectacular proof that magic really does exist. This street-bred theater/circus company offered feats, passion and grace that seemed beyond us mere mortals. With Cirque’s newest production, “Quidam,” we have proof that magic has its limits. While this show still puts other circuses and performance art companies to shame, compared to the standards of previous Cirques, this is something of a letdown which won’t keep crowds from filling the bigtop, and cheering enthusiastically on the production’s three-year North American tour. By now, the Cirque du Soleil format is well-established: After some initial audience taunting from the principal clown (this year it’s John Gilkey, a promising comic who is nonetheless still David Shiner-Lite), the show then moves to the main stage, where characters playing ordinary people are drawn magically into the world of the circus. The program unfolds through a series of acts some by the house troupe, others by performers from around the world linked by the thinnest of plots and held together by a troupe who are equal parts charming and menacing. With “Quidam,” the menacing aspects are more pronounced. The show opens with the house troupe in white body suits that look like quarantine outfits, and during several other acts, there is an unmistakably apocalyptic feel. Even the plot structure is unsettling. A young girl (11 -year-old Audrey Brisson-Jutras, daughter of music director Benoit Jutras) is lured from her boring family by Gilkey and other clowns, including a headless, umbrella-holding body that is the show’s logo, into the magical circus world. The plot, however, isn’t what crowds around the world come to see: It’s the incredible performers who defy gravity, death and various other laws of physics. “Quidam’s” problem apparent only to those who’ve experienced the previous shows is that too many acts this year seem earth-bound. From the house troupe’s not especially challenging jump-rope routine, to aerialist Petra Sprecher (who seems more adept at swinging than flying), to a thoroughly uninspiring trio of clowns Les Macloma too many acts in “Quidam” seem better suited to busking on the nearby Third Street Promenade. Cirque du Soleil acts should soar, and too many this year don’t. That’s ironic, since flight seems to be one of this year’s themes. Set designer Michel Crete has created a spectacular stage, with five overhead rails that appear to be merely decorative but turn out to be the conveyance that flies the acts onto the stage. It’s a brilliant bit of stagecraft, bringing the acts in airborne, providing at least an initial sense of wonder. And in quite a few of the 13 acts that performed Thursday (the elevated hand balancing a gymnast featured in the program was a no-show), the magic is apparent. Aerial contortionist Isabelle Vaudelle twists, wraps and suspends herself from a ceiling-to-floor-length piece of red fabric. In keeping with the end-of-the-world theme, she at times seems to be encased in a burial shroud. Maybe it’s because she frequently looks distressed, or maybe it’s because at other times she so effortlessly seems to float above the stage, you are enraptured by her. Just as captivating is the act called simply Manipulation , in which two performers toss, balance, roll and, well, manipulate, shiny red balls. At first it seems like a fairly mundane act, but the more things they do with the balls (sometimes they seem light as air, sometimes leaden, sometimes bouncy, sometimes fragile), the more compelling the act is. Best of all, though, is one that is again seemingly simple. Called Main a Main, Vis Versa, the act features a man and a woman (Yves Decoste and Marie-Laure Mesnage) who perform a slow, sensuous, impossibly strenuous act of strength and balance. Their bodies powdered a cadaverous white, they fulfill our desire for superhuman feats, her body stretching out parallel to the ground while only her shoulders rest on his body. Then, in contradiction to the usual strong-man/lithe-woman formula of most circuses, she lifts him as he floats over the ground. Adding to the somber yet thrilling mood are the members of the Cirque company who watch all of this while suspended from the roof of the tent, wearing long, flowing white gowns. They seem like angels, or saints, or perhaps martyrs, watching those mortals below struggling against the laws of nature. It is chilling and uplifting all at once, and ranks with the best of previous Cirque acts. One other act is especially notable: the house troupe’s Banquine, in which 14 performers execute precise gymnastic and strength routines, sometimes flying through the air, sometimes building human towers four-people high. The fact that it is a classic circus act in fact its roots go back to the Italian Middle Ages detracts not at all from the skill and expertise these artists manifest. Underscoring all of this is Jutras’ evocative music, Luc Lafortune’s mood-establishing lighting and, in particular, Franco Dragone’s skilled direction: He brings the acts on and off the circular stage and keeps various clowns and actors onstage throughout, sometimes merely observing the action, sometimes providing a counterpoint to it. All of this proficiency will leave the inevitable large crowds going home satisfied. Even after a dozen years, there’s nothing else like Cirque du Soleil, and even in this sub-peak effort, there are substantial rewards. But there’s no getting around the fact this show is short of magic, and magic is what we expect from this company.